Magnetic electrical cord connector



Dec. 1, 1964 R. E. DENNIS 3,159,725

MAGNETIC ELECTRICAL CORD CONNECTOR Filed Oct. 9, 1962 v Rm. 3 4/ 3/ 30 lo 28 5/ 5853 35- 6 i INVENTOR .R/cHARo EDew/v/s BY A 7' 'To/ eA/Evs v a variety ofdisadvantages.

United States Patent 3,159,725 MAGNETIC ELECTRHCAL CORD @(BNNEEITUR Richard E. Dennis, 60178 Dial Way, San Jose, tjalit.

Filed Get. 9, 1962, Ser. No. 229,342 4 Uairns. (Ci. Mitt-61.09)

This invention relates to a detachable electric fixture for magnetically connecting electrical cords comprising a socket element and a coacting mating plug element. V

For a long time, there has been a real need in the art for a means of connecting conventional electric cords to conventional electric sockets through some sort of intervening switch element in which the exposed electrical terminal plates would be non-energized or dead until after the plug element has been joined with the socket element. Such an arrangement eliminates the danger of shocks and improper connections (with possible resulting short-circuiting), and makes possible the containment of all moving components in sealed compartments free from contamination by environmental influences, such as dust, dirt, water,or the like.

While heretofore permanent magnets have been pro posedfor use in fixtures such coupling actuated switch means, such prior art devices have generally suffered from For example, the coupling actuated magnetic fixture described in U.S. Patent 2,573,920 suffers from the disadvantage that both the 7 socket element and the plug element there described require extensive rewiring and circuit redesign since the fixture there described cannot be used with conventional sockets and plugs. Furthermore, in this fixture the permanent magnets are only are required for the conduction of electricity, but also at the same time providepartof the holding force between the plug element and the socket element. Thus, the efliciency and reliability of this fixture depends in large part upon continuous, high-level performance of the permanent magnets.

and very effective electrical cord connector having a coupling'actuated magnetic switch means. This connector comprises, in combination, a socket, element and a com- By the present invention there is provideda simple panion plug element. The socket element contains a pair of male prongs adapted for engagement with a'conventional electrical socket,'while the plug element contains a pair of femalesockets adapted to receive the prongs of a conventional electric plug. Thus the connector of this invention can be used with conventional plugs and sockets Without circuit modification. Infaddition, connection be tween my combination plug elementand socket element is etlectuated by means of a key slot in one element and an interlocking key ,slidably engaging with such key slot located in the other element, thereby eliminating any reliance upon permanent magnet means for joining the respective elements together and'avoiding pulling and tugging during (lisassernbly operations.

through contacting a pair of electrical terminal plates in the plug element with a pair in the socket element by means of paramagnetism.

It is an object of my invention to provide a magnetic electrical cord connector in which a plug element and a socket element are slidably engaged witheach other by means of at least one interlocking key and key slot.

It is an object of my invention to provide a magnetic electrical cord connector comprising a socket element and a plug element which can employ but a single magnet for the purpose of interconnecting a respective pair of terminal plates in each element thereby permitting current to pass from one element to the other.

It is an object of this invention to provide a two element magnetic electrical cord connector which elements are connected together not by means of pushing and pulling but by means of linear sliding action. 7

Other and further objects of this invention will become apparent to those skilled in the art upon a reading of the following specification, taken together with the attached drawings, in which:

FIG. 1 is an exploded view in perspective of a preferred embodiment of the invention;

FIG. 2 is a vertical sectional view taken along line 22 of FIG. 1; p

FIG. 3 is a horizontal sectional view taken along line 3-3 of FIG. 1;

FIG. 4 is a detailed view in perspective of a portion of the switch mechanism shown partially in FIG. 3; and

FIG. 5 is a horizontal sectional View similar to FIG. 3 showing a modification of the embodiment shown in FIG. 1.

Referring to the drawings, there is seen in FIG. 1 a connector of the invention comprising a socket element, herein denoted in its entirety by the numeral lit, and 'a plug element, herein denoted in its entirety by the numeral housing 12 and adapted for engagement with a conventional electric socket 17 (only partially shown). These prongs are conveniently formed from a conductive sheet metal such as copper and are conveniently set into the mating halves 13 and 14 of housing 12 in the manner suggested in F1613. These prongs 16 are then held in ,pla'cewhen the rivet 15 is secured in position when the socket element Ill-is assembled. As a matter of convenience, there'is provided in the top center rear region I of the housinglZ a bracket lh which is mounted in a It is an object of my invention to provide anelectrical cord connector containing an integral coupling-actuated magnetic switch. 7

It is an object of my invention to provide a magnetic electrical cord connector in whicha plug element and a socket element areslidably engaged witheach other.

It is an object ofrny invention to provide a magnetic electrical cord connector adapted for use with co'nven-i tional electric plugs and conventional electric sockets.

It is an object of my invention to provide a coupling actuated magnetic switch in which a pair of electrically used to fasten theface plate 22 (partially shown only) of conventional socket'17. The bracket 13 is conveniently held to the housing 12 by means of arivet 21 extending through the base region-of bracket 18 into the upper half 13 of the housing 12.

conductive, paramagnetically responsive switch elements It isan object of my'zinvention to providea coupling-i actuated magnetic switch in which currentis' conducted I are made conductive by magnet means placed in proximity thereto. 1

from a plug element to a socket element, or vice versa,"

Across the mid-region of flat forward face 23 of housing 12 and runningin a generally vertical direction is a key slot 24, entrance to whichis gained from the edge ofa top hat face 25 of housing 12. Laterally spaced from key slot 24 are a pair of channelslo and 27 which'in the embodiment shown are each equidistant from key slot 24 and parallel thereto; Key slot 24 and channels 26 and 27 are each closed across the flat'bottonrface Z3of housing 12; v .3

In the interior of housing 12 and between mating halves 13 and 14 are positioned a pair of paramagnetically responsive electric switch elements, each herein denoted in its entirety by numeral 29. Each such switch element consists of a bellcrank 30 pivoting on a trunnion 31. Trunnion 31 fits into suitable aligned recesses in mating halves 13 and 14 of housing 12 for pivotal movement. A forward arm 34 of bellcrank 30 is fitted with a slot 32. Loosely fitting into this slot 32 is an electrically conductive rivet 33 in such a way that the head of the rivet rides against the forward bellcrank arm 34 on either side of slot 32. Each rivet 33 has its end seated in a button 35 of paramagnetically responsive material electrically conductive (i.e., a material such as iron or one of its alloys which is responsive to and attractive by a magnet). Each button 35 is equipped with a pair of stumps 43 (see FIG. 2) which serve to position and retain a button 35 in housing 12. This button is so chambered in mating halves 13 and 14 that it can ride forwards and backwards, to and away from the rear wall 35 and 37 of channels 26 and 27, respectively. Bellcrank 30 is electrically conductive.

At the point where button 35 would contact each channel rear wall 36 and 37, such rear wall is removed so that at this point in each rear wall 36 and 37 is a pair of holes 38 and 39 (one each in channels 26 and 27, respectively). Thus, the forward face 4t) of 'eachbutton is exposed. Between the rear of slot 32 and axle 31 on the side of bellcrank 36 facing towards the front face 23 of housing 12 is butted a compression spring 41 (paired). Forward motion of a button 35 is limited by means of its stumps 43 whichengage a suitable flange inside housing 12 when the button 35 has progressed forward to the maximum desirable extent (which is usually just enough to permit the face 40 of a button to project just beyond the rear wall 36 and 37 of channels 38 and 39, respectively. Each compression spring 41 is seated ina suitable slot in mating halves 13 and 14 of housing 12. This compression spring tends to yieldingly position each button 35 back away from each hole 38 and 39.

The rearward arm 42 of bellcrank 30 is crimped or set at an angle so that when bellcrank 30 turns on trunnion 31, and respective buttons 35 ride forward compressing respective springs 41, the crimped end 44 of rearward arm 42 of each bellcrank 30 contacts the rear end of male.

prong 16. Observe that it is onlywhen a button 35 is drawn forwardthat associated cr'imped end 44 contacts a male prong 16; for should the button be forced backward as from an external force applied through hole 38 or hole 39, the crimped end 44 rides up against an internal wall of housing 12 in the manner, shown in FIG. 3.

The mating plug element has a housing 45 composed of mating halves 46 and 47 which in the completed plug 11 are held together by rivet 48. Positioned in a rear wall 49 of housing 45 is a pair of female sockets 50 adapted to receive the male prongs 51 of a conventional electrical plug 52. Each such socket 50 is conveniently formed of a strip of conductive material such as a 'strip' of copper sheeting suitably bent so as to fit into a pair of aligned recesses positioned in the interface between mating halves 46 and 47 of housing 45 in the manner shown, for example, in FIG. 3. g

In the fiat rear wall of housing 45 and laterally spaced from one another is positioned a pair of button magnets 53 which are of the-permanent magnet type and are constructed of an electrically conductive material. The lateral distance between button magnets 53 is such as to align them with channels 26 and 27 in socket 10, and the distance which these respective button magnets project from the rear wall of housing 45 is slightly less than the respec tive depth of each channel 26 and 27. Between each respective button magnet 53 and one of the socket elements 50 (paired) is positioned a generally U-shaped leaf spring 56, which pair of springs is constructed of electrically conductive material, such as copper alloy or the like.

yConveniently, each spring can be riveted by'means of a rivet 56 to the rear of each button magnet 53. Note that the rear of each button magnet 53 is equipped with a pair of stumps 58 which ride in slots positioned in the mating halves 46 and 47. Button magnets 53 are thus equipped to move slightly in housing 45 in order to seat themselves when they are (later) engaged with buttons 35.

Positioned mediately between button magnets 53 and formed into the material of which the housing 45 is constructed is a straight, vertically positioned key 54 which mates and interlocks with key slot 24 of socket element 19 when plug element 11 is slidably engaged with the socket element 10. Since, as noted above, the bottom of socket element 10 has no key slot or channel openings, the key 54 can only be interlocked with key slot 24 by engaging the respective plug element 11 with socket element 10 by bringing the bottom of plug element 11 (and its associated key 54) up to the top face 25 of socket 12 and the translating in a vertical direction the plug element 11 with regards to the socket element 10 so as to engage and interlock the key 54 with the key slot 24. Of course, as the key slides into key slot 24, the button magnets 53 come to ride in channels 26 and 27.

When the button magnets 53 become aligned with magnetically responsive buttons 35, the latter are attracted to the former and physically move toward the same so that the face 40 of each button 35 physically contacts the face 55 of each button magnet.

Face to face alignment of each respective button with the other (each respective face of course being flat) is assured by the manner in which not only the pair of buttons 35 .are mounted but also by the manner in which the pair of button magnets 53 are mounted.

In FIG. 5 is shown a modification of the embodiment shown in FIG. 1. There is provided on the forward face 57 of a plug 58 a key 59 which is adapted to mate and interlock with a key slot 60 in the forward face 61 of socket 62 in the manner shown in the embodiment of FIGS. 1-3. In this embodiment prime numbers are used to indicate parts corresponding to those in the embodi ment shown in FIGS. 1-3. Thus, the plug element 58 contains a pair of female sockets 50 which are connected with a pair of conductors 63 which are non-magnetic through the interconnection provided by a pair of leaf springs 56'. Similarly, the socket element 62 contains a pair of male prongs 16 which are each separately electrically connected to each of a pair of electrically con ductive buttons 35' through the conductive medium provided by a pair of bell cranks 30. The bell cranks 30' operate in the manner of the bell cranks 30 in the em bodiment shown in FIGS. 1-3 except that the buttons 35 are moved forward into engagement with the conductors 63 by means of a single magnet 64 carried in the forward edge 65 of key 59. The forward movement of the buttons 35' is accomplished by means of a U-shaped member 66 so positioned in socket 62 that the forward edges of such element each engage a bellcrank 30' behind the point where each bellcrank 30' is connected to each button 35 in the manner shown in FIG. 5. Through the mid-region of the base of electrically non-conductive U-shaped element 66 a shaft 67 is connected. Shaft 67 in turn serves to link U-shaped element 66 with magnetically responsive plate 68 of paramagnetically responsive material. Plate 68 is positioned in the bottom 69 of key slot 60 so as to be opposite magnet 64 when the key of plug 58 is engaged with the key slot of socket'62. Shaft 67 is journailed through housing wall 70 in socket 62 for reciprocatory motion. Thus, when the plug 58 is engaged with the socket 62, magnet 64 draws magnetically responsive plate 68 forward in close proximity to, or even actual engagement with, magnet 64. Such forward movement of the shaft 67 causes U-shaped element 66 to move the buttons 35' forward against theyielding bias of compression springs 41' thereby causing the buttons 35 to con-- tactconductors 63 and complete the electrical connection between each pair of female sockets 50' and male prongs.

16' so as to make the detachable electric fixture plug 68 and socket 62 operative. In this embodiment it will be [appreciated that but a single magnet 64 is employed inin the embodiment invention comprises a socket element and a contacting plug element. The socket element contains a plurality of necessary components including a magnetically permeable, electrically non-conductive socket housing a pair of male prongs rearwardly projecting from said housing and adapted for engagement with a conventional electrical socket; at least one straight key slot running across a flat through said flat forward face; a pair of spaced paramagnetically responsive electrically conductive switch elements, each one mounted in the interior of said socket housing for reciprocatory motion through and away from one of said apertures, each such switch'element'being adapted to conduct electricityonly when it has been moved to approximately the surface of said flat forward face; yielding means urging said switch elements away from the surface of said flat forward face;-and a pair of electrically conductive connecting means, each one joining one of said male prongs with one of said switch elements.

The plug element, like the socket element, also contains a variety of necessary'components including an electrical- V ly non-conductive plug housing a pair of female sockets opening through a rear face of said housing adapted to,

' receive the male prongs of a conventional electrical plug;

at least one" interlocking key on a flat forward face of said "plug housing, each such key being adapted to slidably enforward face of said socket housing a pair of apertures gage one of said key slots in said socket element; perma- While the foregoing description shows what is deemed to be the most desirable embodiment of the invention,

it will be understood that various changes in construetion can be made, if desired, without departing from the spirit and scope of this invention. It is not intended that the foregoing description should be limited to the exact details shown, nor to anything less than the whole of the invention limited onlyby' the appended claims,

The :claims are: f 1. A detachable electric fixture comprising: (a) a magnetically permeable electrically non-conductive housing, (b) male prongs projecting from one face of said housing for engaging a conventional socket, (0) female sockets mounted in another face of said housing to receive male prongs of a conventional (d) permanent magnet means in said housing, (e) paramagnetically responsive elements mounted in said housing to make electrical connection between said prongs and said female sockets,

(f) a pivotally mounted switch means associated with.

at least one of said paramagnetically responsive elements and a male plug, and I (g) said paramagnetically responsive elements conducting electricity only when said magnet means is placed in close proximity to said elements to actuate said switchmeans. I 2. A detachable electric 'fixtu're comprising a socket element and a coacting mating plug element, said socket element containing: 7 I v 'f('a) ja magnetically permeable, electrically non-conductive; socket'housing, I

said plug element containing:

(b) a pair of male prongs rearwardly projecting from said housing and adapted to engage with a conventional electrical socket,

(c) at least one key slot running across a flat forward face of said socket housing,

(d) a pair of paramagnetically responsiveswitch ele ments mounted in the interior of said socket housing and adapted to conduct electricity only when external magnet means is applied to said flat forward face of said socket housing,

(e) a first pair of laterally spaced electrical terminals communicating with said flat forward face of said socket housing from the interior thereof,

(f) a pair of electrical conductor means, each one joinface of said housing and adapted to receive the male prongs of a conventional electrical plug,

(c) at least one interlocking key on a flat forward face of said plug housing, each such key being adapted to slidably engage one of said key slots on the flat forward face of said socket housing, j

(d')' permanent magnet 'means positioned in the said fiat'forward face of said plug housing adapted to place each switch element in said socket element in an electrically conductive position when said plug housing is engaged with said socket housing,

(2') a record pair of laterally spaced electrical terminals communicating with said flat forward face of said plug housing from the interior thereof,'each one adapted to engage one of said first electrical terminals of said socket element when said plug housing is engaged with said socket housing,

' (f') a pair of electrical conductors, each one joining v in series one of said female sockets with one of said second electrical terminals.

3. A detachable electric fixture comprising a socket element and a coacting mating plug element, said socket element containing:

" (a) a magnetically permeable, electrically non-conductive socket housing, (b) a pair of male prongs rearwardly projecting from said housing and adapted for engagement with a fade,

from the surface of said flat forward face, and

(g) 'a pair of electrically conductive connecting means, 7 each one joining one of said male prongs with one 'of said switch element's,

(a') an electrically non-conductive plug housing,

(b') a pair of female sockets opening through a rear face of said housing adapted to receive the'male prongs of a conventional electrical plug, '(c). at least one interlocking key on a flat forward face of said plug housing, each such key being 'adapted to slidably engage one of said key slots in said socket element, i s

V vto approximately the surface of said flat forward (f) yielding means urging said switch elements away I (d') apair of spaced, electrically conductive, perma-. I

nent magnet means positioned in said flat forward face, each one adapted to attract and move one of said sockets switch elements into electrically conductive association with said magnet means when said plug housing isengaged with said socket housing.

(e') a pair of electrically conductive connecting means, each onejoining one of such female sockets with one of said magnet means.

4. A detachable electric fixture comprising a socket element and a coacting mating plug element, said socket element containing:

(a) a magnetically permeable, electrically non-conductive socket housing,

(b) a pair of male prongs rearwardly projecting from said housing and adapted for engagement with a conventional electrical socket,

(c) at least one straight key slot running across a flat forward face of said socket housing,

(d) a pair ofapertures through saidflat forward face,

(e) a pair of spaced electrically conductive switch elements, each one mounted in the interior of said socket housing for reciprocatory motion through and away from one of said apertures, eachsuch switch element being adapted to conduct electricity only when it has been moved to approximately the surface of said flat forward face,

(f) yielding means urging said switch elements away from the surface of said fiat forward face,

(g) a pair of electrically conductive connecting means, each one joining one of-said male prongs with one of said switch elements, and

(h) a paramagnetically responsive element positioned in the bottom face of one key slot, said paramagnetically responsive element being mounted for reciprocatory motion toward and away from approximately the surface of the bottom of such key slot and being interconnected with each one of said pair of switch elements by electrically conductive means so that when said paramagnetically responsive element moves forward each of said switch elements moves forward to an electrically conductive position,

said plug element containing:

(a) an electrically non-conductive plug housing,

(5') a pair of female sockets opening through a rear face of said housing adapted to receive the male prongs of a conventional electrical plug,

(0') at least one interlocking key on a flat forward face of said plug housing, each such key being adapted to slidably engage one of said key slots in said socket element,

(d) a pair of electrically conductive connecting means, each one joining one of such female sockets with one of said magnet means, and

(e') a permanent magnet means positioned in a forward face of a key and being adapted to attract and move the paramagnetically responsive element of said socket element so as to produce electrically conductive association of each of said switch elements of said socket element with one of said pair of female sockets of said plug element when said plug housing is engaged with said socket housing.

References Cited in the file of this patent UNITED STATES PATENTS 2,234,982 Ross Mar. 18, 1941 2,298,313 Ross Oct. 13, 1942 2,448,832 Ross Sept. 7, 1948 2,573,920 McLeod Nov. 6, 1951 FOREIGN PATENTS 562,896 Italy May 21, 1957 

1. A DETACHABLE ELECTRIC FIXTURE COMPRISING: (A) A MAGNETICALLY PERMEABLE ELECTRICALLY NON-CONDUCTIVE HOUSING, (B) MALE PRONGS PROJECTING FROM ONE FACE OF SAID HOUSING FORA ENGAGING A CONVENTIONAL SOCKET, (C) FEMALE SOCKETS MOUNTED IN ANOTHER FACE OF SAID HOUSING TO RECEIVE MALE PRONGS OF A CONVENTIONAL PLUG, (D) PERMANENT MAGNET MEANS IN SAID HOUSING (E) PARAMAGNETICALLY RESPONSIVE ELEMENTS MOUNTED IN SAID HOUSING TO MAKE ELECTRICAL CONNECTION BETWEEN SAID PRONGS AND SAID FEMALE SOCKETS, (F) A PIVOTALLY MOUNTED SWITCH MEANS ASSOCIATED WITH AT LEAST ONE OF SAID PARAMAGNETICALLY RESPONSIVE ELEMENTS AND A MALE PLUG, AND (G) SAID PARAMAGNETICALLY RESPONSIVE ELEMENTS CONDUCTING ELECTRICITY ONLY WHEN SAID MAGNET MEANS IS PLACED IN CLOSE PROXIMITY TO SAID ELEMENTS TO ACTUATE SAID SWITCH MEANS. 